EP0094137A2
Expired / Lapsed
EP
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High-pressure sodium discharge lamp
Assignee: Koninklijke Philips NV
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Filing: 1983-05-06
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Granted: —
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Expires: 2003-05-06
Abstract
Abstract The invention relates to a high-pressure sodium lamp provided with an elongate discharge vessel in which the pressure P in the operative condition of the lamp is at least 17010 3 Pa. The lamp is suitable to be operated with a power of periodically alternating value, which power comprises at least one component having a frequency v i which satisfies i - 0,45 ≦ 2.35 v i Le/e ≦ i + 0,45 where i is an integral positive number, c is the speed of sound in the gaseous part of the filling and L e is the effective length of the discharge vessel. According to the invention, the relation is satisfied: Mv i f i P . d ≦ 185, in which Mv i is the modulation depth of the power component having a frequency v i , f i is a geometric lamp factor and d the average inner diameter of the discharge vessel. In this manner, the operation of the lamp is free of arc instabilities due to longitudinal acoustic resonances.
Inventors
- 👤 Rudolf Lambertus Adrianus Van Der Heijden
- 👤 Jan Willem Frederik Dorleijn
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 19:11
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/84; H01J61/88; H01J61/82; H01J61/825
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
234 words
A high-pressure sodium discharge lamp provided with an elongate discharge vessel which encloses a discharge path and which vessel has an effective length L e 2 and, over at least 3 of the discharge path a cross-section S of constant area, in which vessel two electrodes are arranged each having an end, between which ends the discharge path extends, this lamp being suitable to be operated in operative condition with a power of periodically alternating value, this power comprising one or more power components sinusoidally varying with time and at least one component having a frequency V i for which it holds that i -0.45 ≤2.33 V i Le/c ≤ i + 0.45, where i is an integral positive number and c is the average speed in m/s of propagation of sound waves through the gaseous part of the filling of the discharge vessel in the operative condition of the lamp, characterized in that the filling in the operative condition has a pressure P of at least 170 10 3 Pa and in that for each value of i the relation M V i . f i . P . d ≦ 185 is satisfied, in which M V i is the i modulation depth of the power component having frequency V i , f i is a geometric lamp factor and d is the mean inner diameter of the cross-section S in metres.
Claim 2
Dependent Claim
234 words
A high-pressure sodium discharge lamp provided with an elongate discharge vessel which encloses a discharge path and which vessel has an effective length L e 2 and, over at least 3 of the discharge path a cross-section S of constant area, in which vessel two electrodes are arranged each having an end, between which ends the discharge path extends, this lamp being suitable to be operated in operative condition with a power of periodically alternating value, this power comprising one or more power components sinusoidally varying with time and at least one component having a frequency V i for which it holds that i -0.45 ≤2.33 V i Le/c ≤ i + 0.45, where i is an integral positive number and c is the average speed in m/s of propagation of sound waves through the gaseous part of the filling of the discharge vessel in the operative condition of the lamp, characterized in that the filling in the operative condition has a pressure P of at least 170 10 3 Pa and in that for each value of i the relation M V i . f i . P . d ≦ 185 is satisfied, in which M V i is the i modulation depth of the power component having frequency V i , f i is a geometric lamp factor and d is the mean inner diameter of the cross-section S in metres.
Claim 3
Dependent Claim
64 words
A lamp as claimed in Claim 1, in which the discharge vessel is substantially symmetrical with respect to a plane at right angles to the longitudinal axis of the discharge vessel, characterized in that the same insertion depth PB is associated with each electrode and in that in the operative condition of the lamp, for each even value of i the relation is satisfied:
Claim 4
Dependent Claim
33 words
A lamp as claimed in Claim 1 or 2, characterized in that in the operative condition of the lamp the relation is satisfied : MV i . f.. P . d ≦ 140.
Claim 5
Dependent Claim
44 words
A lamp as claimed in Claim 1, 2 or 3, characterized in that the operating power of the lamp is composed of one or more current and voltage components sinusoidally varying with time, the frequencies of which all amount to at least 20 kHz.
Claim 6
Dependent Claim
54 words
A lamp as claimed in anyone of the preceding Claims, the consumed power of which in the operative condition is at most 100 W, characterized in that in the operative condition of the lamp the pressure in the discharge vessel is at least 300 10 3 Pa and at most 1600 10 3 Pa.
Claim 7
Dependent Claim
137 words
An arrangement for operating a high-pressure sodium discharge lamp as claimed in any of the preceding Claims, which lamp is provided with an elongate discharge vessel which encloses a discharge path and which vessel has an effective length L and over at least 3 of the discharge path a cross-section S ofconstant size, characterized in that the arrangement is provided with means for operating the lamp with a power of periodically alternating value, this power comprising one or more power components sinusoidally varying with time and at least one component having a frequency V i for which holds that where i is an integral positive number and c is the average speed in m/s of propagation of sound waves through the gaseous part of the filling of the discharge vessel in the operative condition of the lamp.
References Cited (Backward Citations)
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